.357 Mag load check. Thanks

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WyoGunner

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I just finished loading some .357 145gr Hornady XTPs with small pistol mag primers and 7.9gn of Unique. The recipe in my borrowed Speer Reloading manual gives me a range of 7.7 to 8.2 but does not use small pistol mag primers. Does anyone see a problem with this load? I am starting to get a little paranoid after reading some other posts about dangerous loads, ect. Thanks in advance
 

WyoGunner

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No, they are just small pistol mag primers. I have kind of abandoned the whole small rifle primer idea. Well... at least until run out of small pistol mag primers. :) Just kidding. Thanks for the check contender. As always, you have been a great help.
 

Rick Courtright

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Hi,

Please double check the Alliant site before taking my word cuz I'm looking at an older Alliant book right now:

They show a load w/ a Federal 200 (SPM) primer, 158 gr JSP and 7.8 gr Unique as a max.

So you're right close to the edge by that book (the slightly lighter bullet should offset that extra tenth of a grain of powder.) "Shoot one, examine closely, then decide whether to shoot the others" would be my personal drill in a situation like this...

Rick C
 

Snake45

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The mag primers with that much Unique is the only thing that worries me a little. You probably won't blow up a Blackhawk with that load, but like Rick says, shoot ONE and take a good look at the case, the primer, and the bore after that. And take note of how hard or easily it extracts.
 

DGW1949

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Watch you're seating depth.
The crimp grove on simular weight bullets made by different manufacturers are often in different places. A max load that is safe with one bullet, might not be with another.

DGW
 

WyoGunner

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I am quite embarrassed, but I made a mistake in my original post. The bullets are actually 158gr Hornady XTPs. I loaded them with small pistol mag primers and 7.9 gns of Unique. Considering Hawkeye's post, I am starting to think that I might be in the danger zone. I loaded the rounds based off of the #11 Speer reloading manual which gives a range of 7.7 - 8.2gns. The Alliant Reloaders Guide lists the max charge as 7.7 with the CCI 500 standard small pistol primer. Even without the mag primers, I am in the danger zone with this load according to Alliant. How is there so much variance between the two sets of data? Do you think my load is unsafe?
 

Snake45

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I see you have GP 100 listed in your sig line, so I'm assuming that's what you'll be shooting them in.

I doubt you'll blow the gun up, but as stated before, light one off and then take a careful look at everything.

Also note that reloading recipes of yesteryear were in some cases much stiffer than what's recommended today, yet those loads were safe in guns that aren't as strong as today's.
 

dougader

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Some primers are hotter than others. Some mag primers are hotter than others.

IME, the CCI mag primers are hotter than, for example, Federal mag primers. Which primers are you using?

The current Speer manual (#14) lists the MAX load with Unique and their 158 grain bullets at 7.7 grains.

I don't know how many you loaded, but I'd pull them and work up a load from about 7 grains with those mag primers.

People got real cautious when the discussion was about switching small pistol primers with small rifle primers. Well, the loading manuals are all pretty clear about working up slowly from a start charge and going back and starting over when you change any component, including the primer.

Here you've got a Hornady bullet, older Speer data and magnum primers. You've got three small changes to the recipe. And others here are probably right about you not having a problem, given you have a stout revolver but who knows unless they've used this exact recipe before?

Speer #14 also lists OAL from 1.570" - 1.575". What's the length of your loaded rounds?

I'd pull them and start over.

FWIW, I am one of the crazy nuts that use SR primers in the place of SP primers in some loads. But I never start with a MAX or above MAX charge of powder with them.

I would have no problem using mag pistol or small rifle primers in a 357 mag load... but with the listed starting charge, not a max charge, of powder. In this case, Speer #14 lists 6.9 as the starting charge for 978 fps from a 6" revolver.
 

WyoGunner

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I loaded them with CCI 550's. OAL is 1.565" on my rounds. Speer #11 gives a SAAMI OAL of 1.590". I only loaded 100 rounds, so I will just pull them and reload them at 7.1gns. Any objections? I was actually just about to walk out the door and test them before I read Doug's post.
 

dougader

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Speer 11 was my favorite reloading manual for many years. Back then, though, they tested loads with the copper crusher method and listed max pressure in CUP (copper units of pressure) as opposed to the more sensitive and accurate psi readings they use now. So you do see a bunch of loads that are lower than they were before.

Look at the 357 mag data with Blue Dot powder. I used to load 125 gr JHP bullets with 14.5 grains of BD powder. Those were max loads in my gun with standard primers. IIRC the Speer 11 data was max at 15 or 16 grains BD with mag primers. Now the MAX charge listed in Speer 14 (13 grains) is below the Speer 11 starting charge.

I wouldn't have a problem with 7.1 grains and magnum primers.
 

dougader

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BTW, my problem with primers is the opposite of yours. I have plenty of small pistol primers but can't find small rifle primers.
 

WyoGunner

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Thanks for the info dougader. I am brand new into reloading and I am using my Uncle's RCBS piggy back press and his Speer 11 manual. This little mix up with data has made me realize that their are a lot of variances between manufacturers and that I need to get more current info. Who would have thought there would be so much difference between the 11th and 14th editions. So if the new max is under the 11th ed starting charge, were re-loaders in danger when they used the old data or is this just the result of more liability on manufacturers?

We can't find small pistol primers to save our lives in WYO. In contrast, rifle primers can be found.
 

WyoGunner

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I tested .357 mag loads with 7.1gns of Unique and small pistol mag primers. I had no problems whatsoever. I am gonna bump the load up to 7.4gns and go with it. I had some .38s loaded with both small and small mag primers and I couldn't even tell the difference between the two types of rounds. I am starting to think the primer type (mag/std) doesn't have a whole lot to do with the load. I think they are important, but no where near as important as the bullet size/type and the powder charge. Even so, I am glad I started out low instead of learning the hard way. Thanks for everything dougader.
 

dougader

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You probably won't ever feel a difference between std and mag primers when shooting low pressure rounds.

But don't be fooled by that with high pressure rounds. In Speer 14 you see a lot more information than older manuals as well. One of the things they talk about is how excessive pressure can be happening even if you don't have the usual signs like flattened primers, sticky case extraction or bulged cases.

I did see excessive pressure signs once when loading 140 grain Sierra jhp's and a max load of Blue Dot I had worked up with std primers and, inadvertently, switched to CCI 550 mag primers. I got flattened primers and very sticky case extraction from a S&W 686. I pulled the rest of those and started over. I didn't realize what I had done until I got home. And, I couldn't feel a difference when I shot them, either. They felt hot, but just the same as other heavy 357 mag loads.

I saw no high pressure signs with my 125 jhp over 14.5 gr Blue Dot loads, but that doesn't mean they weren't over pressure. I just had a gun strong enough to handle it.

Glad to hear your 7.1 grain loads worked out well. I agree about working your load up in small - like .2 grain - increments and finding a sweet spot for your gun. Look for your most accurate load, not necessarily the one with the highest velocity.
 

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